ELECTRONICALLY CONTROLLED BRAKE SYSTEM(w/ Vacuum Brake Booster), Diagnostic DTC:C1405, C1406

DTC Code DTC Name
C1405 Open or Short in Front Speed Sensor RH Circuit
C1406 Open or Short in Front Speed Sensor LH Circuit

DESCRIPTION

Refer to DTCs C1413 and C1414.

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DTC No. Detection Item DTC Detection Condition Trouble Area Note
C1405 Open or Short in Front Speed Sensor RH Circuit

Either of the following is detected:


  • An open in the speed sensor signal circuit continues for 0.5 seconds or more.

  • With the +BS terminal voltage 9.5 V or more, the sensor power supply voltage decreases for 0.5 seconds or more.

  • Front speed sensor RH*1

  • Front speed sensor RH (front axle hub sub-assembly RH)*2

  • Front skid control sensor wire RH*2

  • Skid control ECU (brake actuator assembly)

  • Wire harness or connector

 -
C1406 Open or Short in Front Speed Sensor LH Circuit

Either of the following is detected:


  • An open in the speed sensor signal circuit continues for 0.5 seconds or more.

  • With the +BS terminal voltage 9.5 V or more, the sensor power supply voltage decreases for 0.5 seconds or more.

  • Front speed sensor LH*1

  • Front speed sensor LH (front axle hub sub-assembly LH)*2

  • Front skid control sensor wire LH*2

  • Skid control ECU (brake actuator assembly)

  • Wire harness or connector

 -

C1405 DTC Detection Conditions
Vehicle Condition
Pattern 1 Pattern 2
Diagnosis Condition - - -
Malfunction Status An open in the speed sensor signal circuit continues ○ -
With the +BS terminal voltage 9.5 V or more, the sensor power supply voltage decreases - ○
Detection Time 0.5 seconds or more. 0.5 seconds or more.
Number of Trips 1 trip 1 trip

Tech Tips

DTC will be output when conditions for either of the patterns in the table above are met.

C1406 DTC Detection Conditions
Vehicle Condition
Pattern 1 Pattern 2
Diagnosis Condition - - -
Malfunction Status An open in the speed sensor signal circuit continues ○ -
With the +BS terminal voltage 9.5 V or more, the sensor power supply voltage decreases - ○
Detection Time 0.5 seconds or more. 0.5 seconds or more.
Number of Trips 1 trip 1 trip

Tech Tips

DTC will be output when conditions for either of the patterns in the table above are met.

WIRING DIAGRAM

Refer to DTCs C1413 and C1414.

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CAUTION / NOTICE / HINT

Note

When replacing the skid control ECU (brake actuator assembly), perform zero point calibration and store system information.

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PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)


    1. Using the GTS, check for any momentary interruption in the wire harness and connector corresponding to a DTC.

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      Chassis > ABS/VSC/TRC > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      FR Speed Open Front speed sensor RH open detection Error or Normal

      Error: Momentary interruption detected

      Normal: Momentary interruption not detected

      		 After a momentary interruption occurs, if there is no momentary interruption for 1 second, it switches from "Error" to "Normal".
      FL Speed Open Front speed sensor LH open detection Error or Normal

      Error: Momentary interruption detected

      Normal: Momentary interruption not detected

      		 After a momentary interruption occurs, if there is no momentary interruption for 1 second, it switches from "Error" to "Normal".

      Chassis > ABS/VSC/TRC > Data List
      Tester Display
      FR Speed Open
      FL Speed Open
      OK
      Normal (There are no momentary interruptions.)

      Tech Tips

      Perform the above inspection before removing the sensor and connector.

      Result
      Proceed to
      OK
      NG (for 2WD)
      NG (for AWD)

    NG (for 2WD)

    INSPECT FRONT SKID CONTROL SENSOR WIRE Click here

    NG (for AWD)

    CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - FRONT SPEED SENSOR) Click here

    OK

  2. READ VALUE USING GTS (FRONT SPEED SENSOR)


    1. Turn the engine switch off.

    2. Connect the GTS to the DLC3.

    3. Start the engine.

    4. Select the Data List using the GTS.

      Click here


      Chassis > ABS/VSC/TRC > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      FR Wheel Speed Front wheel speed sensor RH reading Min.: 0 km/h (0 mph), Max.: 326 km/h (202 mph) Vehicle stopped: 0 km/h (0 mph) When driving at constant speed: No large fluctuations
      FL Wheel Speed Front wheel speed sensor LH reading Min.: 0 km/h (0 mph), Max.: 326 km/h (202 mph) Vehicle stopped: 0 km/h (0 mph) When driving at constant speed: No large fluctuations

      Chassis > ABS/VSC/TRC > Data List
      Tester Display
      FR Wheel Speed
      FL Wheel Speed

    5. Check the speed value output from the speed sensor displayed on the GTS.

      Tech Tips

      Factors that affect the indicated vehicle speed include tire size, tire pressure, and tire wear. The speed indicated on the speedometer has an allowable margin of error. This can be tested using a speedometer tester (calibrated chassis dynamometer). For details about testing and the margin of error, see the reference chart.

      Click here

      OK
      The speed value output from the speed sensor displayed on the GTS is similar to the speed indicated on the speedometer.
      Result
      Proceed to
      OK
      NG (for 2WD)
      NG (for AWD)

    NG (for 2WD)

    GO TO STEP 4 Click here

    NG (for AWD)

    GO TO STEP 7 Click here

    OK

  3. RECONFIRM DTC


    1. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    2. Turn the engine switch off.

    3. Start the engine.

    4. Perform a road test.

    5. Check if the same DTC is output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTCs C1405 and C1406 are not output. A
      DTCs C1405 and/or C1406 are output. B

    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    REPLACE BRAKE ACTUATOR ASSEMBLY for LHD: Click here
    REPLACE BRAKE ACTUATOR ASSEMBLY for RHD: Click here

  4. INSPECT FRONT SKID CONTROL SENSOR WIRE

    B006DBCC07
    *A for RH
    *B for LH
    *1 Front Skid Control Sensor Wire
    *a

    Front view of wire harness connector

    (to Vehicle Side Connector)
    *b

    Front view of wire harness connector

    (to Sensor Side Connector)

    1. Make sure that there is no looseness at the locking part and the connecting part of the connectors.

    2. Disconnect the z21, A16, A25 and/or AA3 front skid control sensor wire connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      for RH
      Tester Connection Condition Specified Condition
      z21 -1 (FR+) - A25 -5 (FR+) Always Below 1 Ω
      z21 -1 (FR+) or A25 -5 (FR+) - Body ground and other terminals Always 10 MΩ or higher
      z21 -2 (FR-) - A25 -1 (FR-) Always Below 1 Ω
      z21 -2 (FR-) or A25 -1 (FR-) - Body ground and other terminals Always 10 MΩ or higher
      for LH
      Tester Connection Condition Specified Condition
      A16 -2 (FL+) - AA3 -3 Always Below 1 Ω
      A16 -2 (FL+) or AA3 -3 - Body ground and other terminals Always 10 MΩ or higher
      A16 -1 (FL-) - AA3 -1 Always Below 1 Ω
      A16 -1 (FL-) or AA3 -1 - Body ground and other terminals Always 10 MΩ or higher

      Note

      Check the speed sensor signal after replacement.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE FRONT SKID CONTROL SENSOR WIRE Click here

    OK

  5. CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - FRONT SKID CONTROL SENSOR WIRE)


    1. Make sure that there is no looseness at the locking part and the connecting part of the connector.

    2. Disconnect the A9 skid control ECU (brake actuator assembly) connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      for RH
      Tester Connection Condition Specified Condition
      A9-31 (FR+) - A25-5 (FR+) Always Below 1 Ω
      A9-31 (FR+) or A25-5 (FR+) - Body ground Always 10 kΩ or higher
      A9-30 (FR-) - A25-1 (FR-) Always Below 1 Ω
      A9-30 (FR-) or A25-1 (FR-) - Body ground Always 10 kΩ or higher
      for LH
      Tester Connection Condition Specified Condition
      A9-18 (FL+) - AA3 -3 Always Below 1 Ω
      A9-18 (FL+) or AA3 -3 - Body ground Always 10 kΩ or higher
      A9-17 (FL-) - AA3 -1 Always Below 1 Ω
      A9-17 (FL-) or AA3 -1 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. INSPECT BRAKE ACTUATOR ASSEMBLY (SENSOR INPUT)


    1. Reconnect the A9 skid control ECU (brake actuator assembly) connector.

    2. Reconnect the AA3 or A25 front skid control sensor wire connector (for vehicle side connector).

    3. Turn the engine switch on (IG).

    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      for RH
      Tester Connection Switch Condition Specified Condition
      z21-1 (FR+) - Body ground Engine switch on (IG) 11 to 14 V
      for LH
      Tester Connection Switch Condition Specified Condition
      A16-2 (FL+) - Body ground Engine switch on (IG) 11 to 14 V

      Tech Tips

      The front speed sensor rotor and front speed sensor are incorporated into the front axle hub sub-assembly.

      If the front speed sensor rotor needs to be replaced, replace the front axle hub sub-assembly with front speed sensor.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE FRONT AXLE HUB SUB-ASSEMBLY Click here

    NG

    REPLACE BRAKE ACTUATOR ASSEMBLY for LHD: Click here
    REPLACE BRAKE ACTUATOR ASSEMBLY for RHD: Click here

  7. CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - FRONT SPEED SENSOR)


    1. Make sure that there is no looseness at the locking part and the connecting part of the connector.

    2. Disconnect the A9 Skid control ECU (brake actuator assembly) connector.

    3. Disconnect the A72 or A73 front speed sensor connector.

    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      for RH
      Tester Connection Condition Specified Condition
      A9-31 (FR+) - A73-5 (FR+) Always Below 1 Ω
      A9-31 (FR+) or A73-5 (FR+) - Body ground Always 10 MΩ or higher
      A9-30 (FR-) - A73-1 (FR-) Always Below 1 Ω
      A9-30 (FR-) or A73-1 (FR-) - Body ground Always 10 MΩ or higher
      for LH
      Tester Connection Condition Specified Condition
      A9-18 (FL+) - A72-3 (FL+) Always Below 1 Ω
      A9-18 (FL+) or A72-3 (FL+) - Body ground Always 10 MΩ or higher
      A9-17 (FL-) - A72-1 (FL-) Always Below 1 Ω
      A9-17 (FL-) or A72-1 (FL-) - Body ground Always 10 MΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. INSPECT BRAKE ACTUATOR ASSEMBLY (SENSOR INPUT)


    1. Reconnect the A9 skid control ECU (brake actuator assembly) connector.

    2. Turn the engine switch on (IG).

    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      for RH
      Tester Connection Condition Specified Condition
      A73-5 (FR+) - Body ground Engine switch on (IG) 11 to 14 V
      for LH
      Tester Connection Condition Specified Condition
      A72-3 (FL+) - Body ground Engine switch on (IG) 11 to 14 V

      Note

      Check the speed sensor signal after replacement.

      Click here

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE FRONT SPEED SENSOR Click here

    NG

    REPLACE BRAKE ACTUATOR ASSEMBLY for LHD: Click here
    REPLACE BRAKE ACTUATOR ASSEMBLY for RHD: Click here